Automatic tank vent valve



J. c. P. DE KRAFFT AUTOMATIC TANK VENT VALVE Fild May 15 1922 2 Sheets-Shes) l 'June 17, 1924.

J. c. P. DE KRAFFT AUTOMATIC TANK VENT VALVE Filed .May 13 '1922 John C. F? De frqff 2 Sheets-Sheet 2 d S 42@v E V' :YQ 'f5 l @Z l m \e 9g k /f 6@ Hm.

INVENTOR.

ff: TTORNEY.

Patented June 17, 1924.

UNITED STATES- PATENT OFFICE.

JOI-IN C. I. DE KRAIEIET, OF IHILADELPI-IIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TG WILLIAM H. BALL, OF DETROIT, MICHIGAN.

i AUTOMATIC TANK "VENT VALVE.

Application filed May 13,

To all 'whom it may concer/rt:

Be it known that I, J oHN C. P. DE Kimrr'r, acitizen ofthe United States, and a resiA dent of Philadelphia, county of Philadelphia, State of Pennsylvania, have invented certain new7 and useful Improvements in Automatic Tank 'Vent Valves, of which the following is a specification.

This invention relates to ar valve device and more particularly to a valve device adapted to close a tank vent forthe storage of oil or volatile liquids within denite pres sure limits and to also permit said tank to be positively closed under all conditions.

In the storage and transportation of gasoline and petroleum products and other vol atile liquids in tanks, tank cars and tank Steamers it is desirable to maintain the tank closed under such pressures as are present under normal conditions, in order to avoid an excessive evaporation and loss of liquid, and to permit the vapors to be vented when these pressures are exceeded or when pressures are generated which might burst the tank, or which prevent it from being filled. When the tank is being emptied it is also necessary to open the vent to prevent a vacuum being generated by the withdrawal of the liquid which would prevent further withdrawal. In certain types of tanks or containers, such as tank Steamers, certain situations may make it necessary to posi tively closeA the tank against the inflow or outflow of liquids or vapors as, for example, in the case of a wreck in which case the vent must be positively closed to prevent the en trance of sea water or the leakage of the liquid being transported. In vthecase of in flammable liquids it is further desirable prevent, as far as possible, all danger of the formation of an inflammable mixture within the tank and the transmission of a dame to such a mixture.

An object of this invention is te provide a valve device for containers of the above type by which the container is maintained closed while the pressure within the tank is within definite limits but which will permit the passage of vapors when the pressure passes these limits.

Another object of the invention is to pro- 1922. Serial No. 560,578.

vide a valve device which will remain closed until either an upper or a lower pressure limit is passed and which is also connected to permit its positive manual closure against venting.

A further object of the invention is to provide a valve device adapted to permit the venting of a container under certain pressure conditions and which will prevent the entrance to said valve device ofr flame, dust and other undesirable matters.

Another object of my invention isto provide a simple and inexpensive double valve structure, each valve acting independently of the other, one valve being moved from its seat upon a definite increase of pressure and the other valve by giving a like motion upon a definite decrease in pressure.

vWith these and other objects in view, the invention comprises the apparatus described and set forth in the following speciiication and claims.

The application is a continuation in part of my application Serial No. A472,374 filed May 25, 1921.

Referring to the accompanying drawings:

Fig. l is a sectional elevation, taken on line l-l of Fig. 2, of a valve device embodying one form of my invention.

Fig. 2 .is a cross section on line 2-2 of Fig. l of the device shown in Fig. l.

Fig. Sis a sectional view of the-device similar to the view in Fig. l but showing the positive closure means in closedposition.

Fig. 4 is an elevation view of the device.

Fig. 5 is a view similar to that of l of a valve device embodying another form of my invention.

Fig. 6 is a view similar to that of Fig. l of a valve device embodying still another form of my invention.

Fig. 7 is a view similar to that of Fig. 5 showing the device of Fig. 5 with the positive closure means in closed position, and,

Fig. 8 is an external elevation of the device shown in Figs. 5 and 7.

ln the present invention a casing in which the valve structure is mounted is in comniunication with the interior of the tank to which it is applied and has also a passage leading to the atmosphere. This passage is,

however, closed by a valve opening into said passage which is pressed into closed position with a delinite pressure and which is opened to permit vapors and gases to be vented to the atmosphere when the pressure within the casing. exceeds. this pressure. The passage is also closed by a valve opening outwardly therefrom which is pressed.` to a closed position on its-.valve seat with a defi! mounted to surround the outlet mouth otl this passage to guardV against the passage ot spray and dustv into the'valve device andto prevent the passage of flame into the valve chamber. 'f

Referring more particularly to the accom;

panying drawings, communication between the interior oll a tank` andthe interior of a valve device casing is provided through a passage- 12 having inward threads 14 adapted Yto receive a threaded exhaust or ventpipe of the tank. The pressure of the vapors and'Y gases in the casing 10 act upwardly on a valve 16 which opens upwardly into a centrally positionedV valve chamber 18 and which is'pressed downwardly onto its valve seat 20 by means of a spring 22., in theA embodiment shown in Figs. 1. 3 and v6, or by means of a weight 23 inthe embodiment shown in Figs. 5 and .7.

When the pressure in the tank, and in the casing 10, exceeds that ot the spring 22 or oi" the weight 23the valve 16 is lifted and the vapors and gases are vented into the valve chamber 18. From the valve chamber 18 the vapors and gases pass outwardly through a number of radial passages 24, the

. walls'of which serve lto support the valve chamber, and enter an annular chamber 26 `from which they are vented to the atmosphere through an annular mouth 28. When the pressure within the casing andrtankis relieved by the venting of the vapors and gases the valve 16 is again pressed onto its seat 2O and the venting o3t`- the vapors is stopped.

lhen the tank is being emptiedA of its contents the pressure of the vapors and gases within the tank is lowered and the valve 16 is pressed the more lirmly onto its seat. To relieve the vacuum created by the removal of the liquid a second'valve 3() is provided on the valvev chamber in such a manner that it opens from the valve chamber to the casing 10 when a definite vacuum or pressure below atmospheric is reached. The valve 30 is normally pressed onto a valve seat 32 by means of a spring 34, in the embodiment of Figs. 1, 3 and67 or by means of a weight 35, in the mlQOdiment shown in Figs. 5 and 7. Accordingly theva-lvef 16 opens to vent the tank when a definite excess pressure is generated in the tank7 andthe valve 30 is opened by the pressure of the atmosphere when a deliniteV vacuum or pressure below atmospheric is present in the tank.

In certain situationsor emergenciesyitmay be desirable to entirely and positivelyv close the vent` to the atmosphere regardless of the conditions within the tank, as, 'for example,

in the case of a wreck at sea when there is danger of'- floodingv the tank with seawater.

For this purpose,"th e mouth of thepassage to theatmosphere may be closed by a" Vertr` cal-ly adjustable valve',v formecbin the modifications shown in Figs. l, B-avndg, cfa ring 36; having a beveled' or valve surface 38 sition by rotating the ringon thef screw threads` 44.

The annular chamber 26 ispreferably` formed bymeanslof acap member 46 hay ing inner screwthreads-48 on its upper inner surface whichlengage corresponding outerscrewthreads 50 on the upper outer surfaceof an inner cylindricaleasing member 52 and closingk the upper open end of the inner casing member 52. The cap is flared outwardly below the screwthreadselS toformV an outer wall 54 of the annular chamber 26;

In the modilications shown in Figs. l. 3"

and 6 the cap isrigidly mounted on the inner casing member.l shown in Figs 5 and?, there is no closing ring suoli as` the ring 36 onV thelower part` of the central casing- 52, an immovable-ring portion 56Lbeing formedintegrally with the;

inner casing 52"and provided with a `valve portion 58. ln this modification, however,A

thecap member 46 is not rigidlymounted on the casing 52 butvmay he screwed downwardly untilavalve surface 60 on itslower edge contacts withthe surface 58y and closes the, chamber 26.

Ascreen 62fis mounted on the ring 86* oi the modification shown in Figs. 1, and 6 or the ring portion 56 offtliegmodiication.

of Figs. 5 andLIin suchV a manner asy to In the modificationy9o onl its upper edgeVV which, in the uppermost llO cover the opening to the chamber 26. The screen is supported on an annular frame 64 which is attached to the ring member by means of screws 66 and has an inwardly projecting flange 68 adapted to rest on an outwardly projecting flange 70 on the lower edge ot the cap member 16 when the ring and cap members are in open position. The screen serves to prevent the entrance of dust and spray into the valve structure and 'lo exclude anyv flame which may be brought into contact with the structure.

ln the form shown in Figs. 1 and 3 the valve 30 is guided in its upward and downward movement by means of a stem Z2 extending upwardly lfrom the upper surface of the valve and movable vertically in a socket 74; of a boss 7 6 extending downward ly from the top of the cap member 116. The upper end ot' the spring 8dis supported by means of a nut 7 8 mounted on screwthreads on the exterior' surface or' the boss .76 the position of the nut 7 8 being secured by means of a lock nut 82.

The lower valve 16 is similarly guided by means of an upwardly extending stem 8/1 which enters, and is vertically movable in a socket 86 formed in the boss 88 extending downwardly from the lower surface of the upper valve 50. The boss 88 is also provided with an exterior screw surface 90 on which are mounted a nut 92 against which the upper end of the spring 22 bears and a loch nut 94 to hold the nut 92 in position, The valves 16 and 30 are also provided with downwardly extending guides 96 and 98, respectively, which slide in Contact with the inner edge of the respective valve seats.

Ordinarily it is desirable to maintain the valve 16 closed against greater pressure than the valve 30. In the above described modiiication this is attained by the action of the spring 22 opposing the action of the spring Se, the valve 30 being pressed against its seat by the difference between the pressure of the spring Se and the pressure of the slightly weaker spring` 22. The tensions of the springs may be adjusted by adjusting the nuts 78 and 92 to adjust the limiting pressures under which the valves open.

ln the modification shown in Figs. 5 and T, the guides for the valves are arranged similarly to that ot Figs. 1 and but weights 23 and 35 are substituted for the springs 22 and Se as described above.

ln the form of the invention shown in Fig. 67 the boss 76 and socket 74C are not carried on the under side of the top oii the cap member i6 but are supported on a spider 102 having an internally screw threaded lower band 104 which engages corresponding outer screwthreads 104 on the upper portion of the valve chamber 18. No

loch nut and supporting nut are required this case, the upper end of the spring 34 being retained by the upper part oi the spider and the adjustment of the spring tension being obtained. by turning the spider and thereby adjusting its position vertically on the valve chamber 46.

ln this modification the lower socket and boss 88 may be carried by a. ring 106 having 4a screwtl'lreaded outer surtace 108 engaging internal screwthreads 110 on the inner surface of the valve chamber 18a instead of being supported from the upper valve 30. The boss 88 is supported on the ring 106 by radial spokes 11,2 against the lower surfaces of which the upper end ot the spring 22 bears. ,ln this form ot ein bodinient of the invention7 the actions of the springs 22 and l0 are independent ol each other and are separately adjustable by adjust-ing the position ot the spider 102 and the ring 106. The working of this form of the invention is otherwise similar to that oi the form of Figs. 1 and 3.

When the above device is mounted on a closed container any vapors under a pressure higher than that for which the device is set are vented by liitting` the valve 16 and flowing into the valve chamber 18 and escaping through the passages 2&1, the annular chamber 26 and the screen to the atmosphere. Similarly when the pressure within the tanlr falls below the lower limit7 atmospheric pressure is transmitted through the passages 24; to the valve chamber 18 and lifts the valve 30 against the downwardly acting pressure and flowing through the passage 12 to the tank.

The invention thereby provides a simple, safe and compact device by which the VYapors may be retained in tank or con tainer under a definite pressure limit and vented when this pressure is exceededn The invention also provides a device which is particularly safe from fires and accidents and effectually guards against the entrance of dirt and similar substances. The downwardly opening form of the annular outlet opening also shields the valve casing from spray and other finely divided materials which tend to be deflected from the outlet opening independently of the screen. The position of the ring on the casing also serves to indicate whether the outlet vent is or open. ving described the invention what l and desire to secure by Letters Patent is:

1, A device of the kind described which comprises a casing having` an opening adapted to communicate with the interior of a container and a port leading to the atmosphere, a valve opening from said casi ing to said outlet port, a valve opening from said outlet port to said casing, each of said valves being operable separately and independently of the operation of the othen comprises a and means for resiliently holding said valves to closed position against pressures within definite limits, ,one of said valves having guide means guided on a cooperating` guide means of the other valve.

2. A device of the hind described which comprises, a casing having an opening .adapted 'to communicate with the interior ot a container' and a port leading to the atmosphere` a valve opening from said cas- .ing` to said outlet port, a valve opening from said outlet port to said casing, each of said valves being` operable separately and independently ot the operation oil the other, and spring means for yieldingly holdingl .Said valves to closed position against pres sure within definite limits, one olE said wives having` a guide stem telescoping in a soclrct on the other valve.

A. device ot the kind described which casing having an opening adapted to communicate with the interior of a container and a port leading` to the atmosphere, a valve opening,l from said casino; to said outlet port, a valve opening` from said outlet port to said casing, each of said valves being operable separately and independently of the operation oit' the other, spring` means for holding said valves to closed position under pressure under deli- Ynite limits and means 't'or adjustingthe pressure of said spring means, one of said valves having a guide stem telescoping in a socket on the other valve.

si. device oli' the kind described which comprises a vent casing adapted to communicate with a closed container, a valve chamber in said casing, a passageway from said valve chamber to the atmosphere, a valve opening from said casing to said chamber, a valve opening from said chamber to said casing', a yieldable means for holdingsaid valves to their seats against a pressure within definite limits and manually operable lmeans for closing` said passageway from the atmosphere.

5. A device of the kind described which comprises a vent casing adapted to communicate with a closed container, a valve chamber in said casing, a passageway from said valve chamber to the atmosphere, valves opening` in 'reverse directions between said vent casing and said valve chamber and yieldably pressed. to closed positions, an annular outlet 'from said passageway and an annular closing;Y ring adapted toy be moved toV position to close said annular outlet.

G. A device of' the kind described which comprises a vent casing adapted to communicate with a container, a valve chamber in said casing, a passageway from said valve chamber to the atmosphere, valves yieldingly pressed to close access to said valve chamber and adapted to permit tlow ot fluid to and from said valve chamber when opened, an ,annular outlet :from said passe jeway, a manually operable closingring Afor said annular outlet and a screen coverinn` said outlet.

7. A device of the kind described adapted to reist su len lateral movements to which inistoble platl'orms-t are subjected which comprises a vent casing adapted to communicate with a container, a valve chamber in said casingl and conimunicr ting with the atmosphere, an inlet valve opening from said chamber to said casing, a guide stem ein tending from said valve, guide socket receiviugI said stem, an ontlet valve opening lo said valve chamber and having a guide siem, and a ,duide socket for receiving said :item mounted on said inlet valve.

8. 1r device of the kind described which comprises a vent casing` adapted to communicate with a container, a valve chamber in said casing` and communicatinpr with the atmosphere` an inlet Avalve openinga from' said chamber to d casing, a guide stem extending; 'from said valve, a guide socket roce' 'iiq said stem. :in outlet valve opening to said valve chamber and having a guide stem, a guide socket r'or receiving said stein mounted on said inlet valve, a spring comprised between said inlet valve and a fixed port and a spring; compressed between said inlet and said outlet valves.

. i). il. device ol' the kind described which comprises a vent casing adapted to communicate with a container, an outlet passage communicating with said casing, outlet and inlet valves between said casing and said passajae2v each oli said valves being' operable separately and independently of the operation oit the other. a spring pressing said inlet valve to its seat and a spring` compressed between said inlet valve and said outlet valve.

l0. device et the kind described which comprises a vent casing adapted to communicate with a container, a centrally supported valve chamber, passages extending radially from said chamber to the atmosphere, a valve opening 'trom said casing inwardly to said valve chamber, a valve openina` trom. said valve chamber outwardly to said casing, a spring` between said outward ly opening valve and a fixed support and a spring; between said inwardly and out-wardly opening' valves.

ll. A device of the hind described which comprises a vent casing adapted to communicate with a container, an annular outlet chamber formed in said casing', a central valve supporting chamber, a number of radial i'iassageways connecting said valve supporting),- chamber and said annular outlet chamber, a valve closing an opening in the upper tace oi said valve chamber and a valve closing` an opening in the lower face of said valve chamber, a spring bearing downwardly on said upper valve and spring compressed. between said upper and said lower valves.

12. A device of the kind described which comprises a vent casing adapted to coinmunicate with a container, au annular outlet chamber formed in said casing and hav-- ing an annular opening., a central chamber hai/'ing an opening in its upper wall and opening in its lower walle upwardly opening valves on said openings, means yieldingllv urging said valves to closing position on said openinga and passages from said central chamber to said annular chamber.

13. A device ot the kind described which comprises a vent casing adapted to communicate with a container, an annular outlet chamber formed in said casing and having an annular opening, a central chamber having an opening in its upper wall and an opening` in its lower walh upwardly opening valves on said openings, means yieldingly urging said valves to closed position on said openings, passages from said central chamber to said annular chamber, and a closing ring adapted to be manually moved over said annular opening to close said annular chamber to the atmosphere.

14. A device of the kind described which comprises a vent casing adapted to com municate with a container and having an annular outlet opening to the atmosphere, valve means arranged to permit vapors and gases to pass from said container to atmosphere and from atmosphere to container when the pressure in said container rises above or falls below definite limits and a closure ring movable manually to close said annular opening from the atmosphere.

l5. A device of the kind described which comprises a vent casing adapted to communicate with a container and having an annular outlet opening to the atnfiosphere. valve means arranged to permit vapors and gases to pass from said container to atmosphere and from atmosphere to said container when the pressure in said container rises above or falls below definite limits, a closure ring movable manually to close said annular vent opening from the atmosphere and an annular screen mounted on said ring and covering said opening when open.

16. A device of the kind described which comprises a vent casing adapted to communicate with a container and having a downwardly opening annular outlet opening to the atmosphere, valve means arranged to permit vapors and gases to pass from said container to atmosphere and from atmosphere to said container when the pressure in said container rises above or falls below definite limits and a manually operable annular closure means for said annular outlet.

17. A device of the kind described which comprises a vent casing adapted to communicate with a containen a centrally positioned chamber in said casing, passages from said chamber to the atmosphere7 upper and lower openings roni said central chamber to said ca ign an upper valve and a lower valve for said openings7 a spider mounted on said central chamber and estending above said upper va ve? a spring compressed between said va se and said spider and a spring between said upper valve and said lower `valve.

18. A device of? the kind described adapted to resist sudden lateral movement which comprises a vent casing adapted to communicate with a container, a cover secured to said casing. a valve chamber in said cas ing and communicating with the atmosphere, an inlet valve opening `from said chamber to said casing, a guide stem extending from said valve, a guide socket on said cover to receive said stem, an outlet valve opening to said valve chamber and having a guide stem and a guide socket for receiving said stein mounted on said inlet valve and a spring between the inlet valve and the underside of the cover.

19. A device ot the. kind described adapted to resist sudden lateral movement which comprises a vent casing adapted to communicate with a container, a valve chamber in said casing and communicating with the atmosphere, an inlet valve opening from said chamber into said casing, a guide stem extending from said valve7 a guide socket receiving said stemt on outlet valve opening to said valve chamber and having a guide stem, and a guide socket Ator receiving said stem mounted on said inlet valve, said guide stems and guide sockets being in substantial alignment with each other.

20. A device ot the kind described adapte ed to resist sudden lateral movement which comprisesi a vent casing adapted to communicate with a container a valve chamber in said casing and communicating with the atmosphere, an inlet valve opening from said chamber into said casing, an outlet valve opening to said valve chamber and having a guide stemi and a guide socket mounted on said inlet valve for receiving said stem.

21. A device oi the kind described which comprises a A adapted to communicate with the interior of a container and a port leading to the atmos phere, a valve opening from said casing to said outlet port.y a valve opening from said outlet port to said casing, each of said valves being operable separately and independent lv of the operation of the other5 and means for holding said valves in closed position against pressures within definite limits, one of said valves having guide means guided on a co-operating guide means of the other valve.

casing having an opening.

22. A device of the kind desofibed adapted `to esist sudden lateral movement to which unstable yphitfoi'ms are subjected which voinpiises a vent easing adapted to Communicate, with a Container, a Valve ehainlei in said Pasing und communicating with the atmosphere, an inlet valve opening fjoin seid Chamber to said easing, aJ guide stern extending ioin said Valve, a guide socket ie'eeiving seid stem7 'en outlet Valve opening to said valve Chamber and having e guide stein and a guide socket for reCeiV- ingr said Stem.

Tfn witness whereof, I have hereunto set my hand at borough of Manhattan, city and State of New York, this 8th day of May,

JOHN C. P. DE KRAFFT. 

